Anne, I agree with what Gaylene says. You need to experiment with different tops and consider how they work for your particular body. No one rule will answer to all.
You and I share some body similarities. And, for whatever it is worth, I have never, ever been able to stand the sight of myself in a tunic top.
Don't get me wrong. I do like tunics on others -- even some others with short legs! But not on myself. I think they make my legs look even shorter, my torso look even longer, as Rute says. Plus, they draw attention to my relatively muscular thighs. I have nothing against my thighs. But at the same time, I don't really want an arrow pointing to them showing how much bigger they are relative to some of my other body parts!
On the other hand, a top that "covers the crotch point" is not a "tunic top" in my mind. Angie used to recommend one to a few inches above the crotch point as the most modern length....vs. the shorter tops which had been around before that. But even one a few inches longer than that would not be a true tunic.
I have always liked wearing tucked tops (with either skirts or pants) if leg lengthening is my top priority. And right now I am loving the semi tuck and faux semi tuck. This lengthens the leg line in front but creates some structural interest and coverage in back.
T & S's advice might make sense if the top just barely covered the crotch point, if the pants and shoes were exactly the same colour or close enough, if the top was relatively similar in colour value, and if the wearer was also wearing high heels. I honestly don't think they hold in other circumstances.